1. Field of the Invention
This invention relates to the use of certain clonidine derivatives to control intraocular pressure, such as the pressure rise which occurs following ophthalmic surgery, non-invasive laser surgery, or other induced or accidental trauma to the eye.
2. Discussion of Related Art
This invention relates to the nonchronic actual and prophylactic control of increased intraocular pressure that frequently occurs as a result of eye surgery, non-invasive laser surgery, or any other form of intentional or accidental trauma to the eye. In particular, this invention relates to achieving such control through the use of certain clonidine derivatives applied topically to the eye immediately before and for a short period after the ocular trauma.
The class of so called clonidines or substituted phenyliminoimidazolines useful in the present method are disclosed in U.S. Pat. Nos. 4,461,904; 4,517,199; 4,515,800; 4,587,257; and 4,646,007; all of which are incorporated herein by reference to the extent that they individually and collectively define generically and name specifically such clonidine-like compounds or such substituted phenylimino-imidazolines. Eye trauma of the kind contemplated here can be by accident, by invasive surgery of any kind or non-invasive such as by laser. In fact the use of the present invention as adjunct to laser surgery or treatment is preferred. The advent of the laser as an ophthalmic surgical instrument has provided physicians with a means of performing non-invasive intraocular surgery, which offers many advantages over conventional invasive techniques previously utilized. While the advantages of performing non-invasive surgery are many, there are complications which arise as a result of the procedure. Among these is an acute postoperative intraocular pressure rise which occurs in 30-80% of eyes undergoing trabeculoplasty, iridotomy, and capsulotomy procedures using Q-switched Argon, Neodymium: YAG or Ruby Lasers. This complication has also been recognized to occur following conventional invasive cataract surgery, occurring following both intra- and extracapsular surgical techniques with or without intraocular lens implantation.
Various studies have shown that hypotensive drugs such as beta-adrenergic blockers, miotics, steroidal and non-steroidal antiinflammatory agents, and carbonic anhydrase inhibitors do not prevent the acute postoperative intraocular pressure increase following the previously mentioned ophthalmic surgical procedures. A need exists, therefore, for an ophthalmic hypotensive agent which is capable of preventing an acute rise and/or decreasing intraocular pressure following both invasive and non-invasive ophthalmic surgery.
Although the foregoing discussion relates to the need for a hypotensive agent in ophthalmic surgical procedures, it is readily apparent that such agents would also be useful in many other ophthalmic conditions involving a requirement to decrease intraocular pressure.